Chemical Evolution far from Equilibrium

Abstract

Chemical instabilities are able to give rise to strange phenomena such as oscillating reaction in homogeneous media. The reaction of hydrogen peroxide and potassium iodate in dilute aqueous sulfuric acid solution, published in 1921 by BRAY (1), is the first experimental evidence of oscillating behavior in an homogeneous chemical reaction. More recently, BELOUSOV (2)(1959) reported sustained oscillations in the oxidation of citric acid by potassium bromate catalyzed by ceric sulfate in dilute aqueous sulfuric acid. This reaction and its variants were extensively investigated by ZHABO- TINSKII (3) in the early 1960’s. The interest in this field becomes more and more intensive (fig. 1). Moreover the experiments are few in which are fulfilled the thermodynamical conditions required to obtain sustained oscillations in chemical reactions: existence of fluxes between the system and its surroundings (table I).KeywordsIodine ConcentrationState DiagramAqueous Sulfuric AcidPotassium IodatePotassium BromateThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.